Titre :

Rapid bacterial mineralization of organic carbon produced during a phytoplankton bloom induced by natural iron fertilization in the Soutern Ocean

Auteur(s) :

Obernosterer, Ingrid [Auteur]
Laboratoire d'océanographie biologique de Banyuls [LOBB]
Christaki, Urania [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Université du Littoral Côte d'Opale [ULCO]
Lefèvre, Dominique [Auteur]
Laboratoire de MicrobiologiE de Géochimie et d'Ecologie Marines [LMGEM]
Catala, Philippe [Auteur]
Laboratoire d'océanographie biologique de Banyuls [LOBB]
van Wambeke, France [Auteur]
Laboratoire de MicrobiologiE de Géochimie et d'Ecologie Marines [LMGEM]
Lebaron, Philippe [Auteur]
Laboratoire d'océanographie biologique de Banyuls [LOBB]

Titre de la revue :

Deep Sea Research Part II: Topical Studies in Oceanography
Part of special issue KEOPS: Kerguelen Ocean and Plateau compared Study

Pagination :

777-789

Éditeur :

Elsevier

Date de publication :

2008-03

ISSN :

0967-0645

Mot(s)-clé(s) en anglais :

Bacterial growth efficiency
Southern Ocean
Natural iron fertilization
Heterotrophic bacteria
High nucleic acid cells
bacterial respiration

Discipline(s) HAL :

Planète et Univers [physics]/Sciences de la Terre/Océanographie
Sciences du Vivant [q-bio]/Ecologie, Environnement/Interactions entre organismes
Sciences du Vivant [q-bio]/Microbiologie et Parasitologie/Bactériologie

Résumé en anglais : [en]

The response of heterotrophic bacteria (Bacteria and Archaea) to the spring phytoplankton bloom that occurs annually above the Kerguelen Plateau (Southern Ocean) due to natural iron fertilization was investigated during ...
Lire la suite >The response of heterotrophic bacteria (Bacteria and Archaea) to the spring phytoplankton bloom that occurs annually above the Kerguelen Plateau (Southern Ocean) due to natural iron fertilization was investigated during the KErguelen Ocean and Plateau compared Study (KEOPS) cruise in January–February 2005. In surface waters (upper 100 m) in the core of the phytoplankton bloom, heterotrophic bacteria were, on an average, 3-fold more abundant and revealed rates of production ([3H] leucine incorporation) and respiration (<0.8 μm size fraction) that exceeded those in surrounding high-nutrient low-chlorophyll (HNLC) waters by factors of 6 and 5, respectively. These differences in bacterial metabolic activities were attributable to high-nucleic-acid-containing cells that dominated (≈80% of total cell abundance) the heterotrophic bacterial community associated with the phytoplankton bloom. Bacterial growth efficiencies varied between 14% and 20% inside the bloom and were <10% in HNLC waters. Results from bottle-incubation experiments performed at the bloom station indicated that iron had no direct but an indirect effect on heterotrophic bacterial activity, due to the stimulation by phytoplankton-derived dissolved organic matter. Within the Kerguelen bloom, bacterial carbon demand accounted for roughly 45% of gross community production. These results indicate that heterotrophic bacteria processed a significant portion of primary production, with most of it being rapidly respired.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Non spécifiée

Vulgarisation :

Non

Collections :

• Laboratoire d'Océanologie et de Géosciences (LOG) - UMR 8187

Source :

Harvested from HAL